Stretching the Inflaton Potential with Kinetic Energy

TL;DR

This paper explores how non-local derivative operators in the inflaton Lagrangian can enable slow-roll inflation with steeper potentials by adding friction, demonstrated through p-adic string theory.

Contribution

It introduces a mechanism where non-local kinetic terms suppress potential curvature, allowing steep potentials to sustain inflation, with explicit illustration in p-adic string theory.

Findings

Non-local operators add friction, enabling slow-roll inflation on steep potentials.

Potential curvature near the turning point is strongly suppressed.

Prolonged inflation achieved with otherwise too steep potentials.

Abstract

Inflation near a maximum of the potential is studied when non-local derivative operators are included in the inflaton Lagrangian. Such terms can impose additional sources of friction on the field. For an arbitrary spacetime geometry, these effects can be quantified in terms of a local field theory with a potential whose curvature around the turning point is strongly suppressed. This implies that a prolonged phase of slow-roll inflation can be achieved with potentials that are otherwise too steep to drive quasi-exponential expansion. We illustrate this mechanism within the context of p-adic string theory.